B Hopper1, B Cameron2, H Li1, S Graves3, J Stenos3, I Hickie4, D Wakefield1, U Vollmer-Conna1, A R Lloyd1. 1. From the School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia. 2. From the School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia b.cameron@unsw.edu.au. 3. Australian Rickettsial Reference Laboratory, Geelong, VIC, Australia. 4. Brain and Mind Institute, Sydney University, Sydney, NSW, Australia.
Abstract
BACKGROUND: A detailed description of the natural history of acute Q fever, caused by infection with Coxiella burnetii, AIM: : To significantly increase understanding of the illness. DESIGN: Subjects with provisional acute Q fever (n = 115) were recruited from primary care in rural Australia, and followed prospectively by interview and blood collection including for serological confirmation. A nested series of subjects with prolonged illness (cases), and those without (controls), were investigated in detail. METHODS: Total phase I and phase II anti-C. burnetii antibodies were detected by complement fixation test; and IgG, IgM and IgA phase I and phase II titres by immunofluorescence. Flow cytometric analysis was conducted to enumerate circulating T cells subsets, B cells, monocytes and natural killer cells. RESULTS: Serological testing confirmed acute Q fever in 73 subjects (63%). The acute illness featured fever, headache, sweats, fatigue and anorexia; and varied widely in severity, causing an average of 8 days in bed and 15 days out of work or other role in the first month of illness. The illness course varied from 2 days to greater than a year. No cases of chronic, localized Q fever infection, such as endocarditis, were identified. Neither severe nor prolonged illness were associated with persistence of C. burnetii DNA, altered patterns of C. burnetii-specific IgG, IgM or IgA antibody production, or altered leucocyte subsets. CONCLUSIONS: The severity of acute Q fever alone predicted prolonged duration. Further studies are warranted to better understand the pathophysiology of prolonged illness after acute Q fever.
BACKGROUND: A detailed description of the natural history of acute Q fever, caused by infection with Coxiella burnetii, AIM: : To significantly increase understanding of the illness. DESIGN: Subjects with provisional acute Q fever (n = 115) were recruited from primary care in rural Australia, and followed prospectively by interview and blood collection including for serological confirmation. A nested series of subjects with prolonged illness (cases), and those without (controls), were investigated in detail. METHODS: Total phase I and phase II anti-C. burnetii antibodies were detected by complement fixation test; and IgG, IgM and IgA phase I and phase II titres by immunofluorescence. Flow cytometric analysis was conducted to enumerate circulating T cells subsets, B cells, monocytes and natural killer cells. RESULTS: Serological testing confirmed acute Q fever in 73 subjects (63%). The acute illness featured fever, headache, sweats, fatigue and anorexia; and varied widely in severity, causing an average of 8 days in bed and 15 days out of work or other role in the first month of illness. The illness course varied from 2 days to greater than a year. No cases of chronic, localized Q fever infection, such as endocarditis, were identified. Neither severe nor prolonged illness were associated with persistence of C. burnetii DNA, altered patterns of C. burnetii-specific IgG, IgM or IgA antibody production, or altered leucocyte subsets. CONCLUSIONS: The severity of acute Q fever alone predicted prolonged duration. Further studies are warranted to better understand the pathophysiology of prolonged illness after acute Q fever.
Authors: Ann E Sluder; Susan Raju Paul; Leonard Moise; Christina Dold; Guilhem Richard; Laura Silva-Reyes; Laurie A Baeten; Anja Scholzen; Patrick M Reeves; Andrew J Pollard; Anja Garritsen; Richard A Bowen; Anne S De Groot; Christine Rollier; Mark C Poznansky Journal: Front Immunol Date: 2022-05-16 Impact factor: 8.786